Ink and method of marking dry cleaned articles therewith



Patented Nov. 2, 1943 INK AND METHOD OF MARKING DRY CLEANED ARTICLES THEBEWITH John Miglarese, Cincinnati, Ohio, assignor to The National Marking Machine Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Application April 7, 1941,

Serial No. 387,237

20 Claims.

In the art of laundry marking there is in general use throughout the civilized world, a laundry marking ink which, when applied in the form of an identification mark to fabrics to be laundered, will, after the completion of the laundering operation, be normally invisible, and when viewed under ultraviolet rays, will be brilliantly fluorescent and clearly legible. However, when said ink is applied to black or dark colored fabrics, the fluorescence and legibility is decreased.

In the so-called dry cleaning now in general use the fabric which is to be cleaned is immersed in a non-aqueous liquid, such as naphtha or chlorinated hydrocarbons, and subjected to agitation and sometimes heat. The cleaning liquid dissolves fats, oils, greases, common food stains, etc., and also removes dust, dirt, etc., leaving the fabric cleaned. After the fabric has been cleaned and all traces of cleaning liquid removed, it is pressed by being subjected to the action of steam at temperatures ranging from 212 to as much as 400 F., and mechanical pressure. Hereafter, when I use the word press, or pressing operation, it will be understood to mean this simultaneous application of steam and mechanical pressure.

The object of my invention is to provide an ink for identification marking of fabrics to be dry cleaned, which ink contains ingredients which are fast to the dry cleaning liquids and will not be appreciably afiectedthereby, carried in other liquid ingredients which will be removed during a dry cleaning operation, and during the pressing operation certain of these above mentioned ingredients will undergo a chemical reaction with steam, this reaction being known as hydrolysis, and as a result of this reaction will become brilliantly fluorescent when viewed under ultraviolet rays, but will be substantially colorless and, therefore, invisible when viewed in ordinary light; and certain other of said ingredients, when subjected to the pressing operation, will be dispersed in and around the fibers of the fabric and will become substantially colorless and translucent and, therefore, invisible in ordinary white light, but will materially increase the fluorescence of the mark when viewed underultraviolet rays in dim visible light.

A further object is to provide an ink of this class having one component consisting of an acid salt of a colorless, fluorescent, basic compound, and another component consisting of a resinous material substantially insoluble in commercial dry cleaning solvents, both of which are carried in a suitable vehicle, and during the pressing operation the acid salt of the colorless, fluorescent, basic compound will be hydrolized to the free base, or parent compound, and be dispersed in and around the fibers of the fabric, and simultaneously the resinous material will be softened and dispersed in and around the fibers of the fabric, and whereby the mark thus produced is substantially colorless and invisible on all types of fabrics in ordinary light, but is extremely fluorescent under the action of ultraviolet rays when viewed in dim visible light.

A further object of my invention is to provide an ink for identification marking of fabrics to be dry cleaned, which is of such a nature that, during the said chemical reaction of hydrolysis occurring during the pressing operation, the colorless, fluorescent, basic compound formed.

is of such a nature that subsequent dry cleaning operations will dissolve and remove it, thus preventing a multiplicity of marks upon the same fabrics.

A further object is to provide an improved method of applying identification markings to fabrics to be dry cleaned, which consists in providing an ink having one component consisting of an acid salt of a colorless, fluorescent, basic compound, and another component consisting of a resinous material substantially insoluble in dry cleaning solvents, and thereafter during the dry cleaning pressing operation, subjecting the fabric and its markings to heat and steam to thereby cause a chemical reaction which hydrolizes the acid salt back to the fluorescent parent compound and also disperses it and the resinous material around the adjacent fibers of the fabric, thereby causing the markings to become substantially colorless and invisible under ordinary light, and brilliantly fluorescent under ultraviolet rays when viewed in dim visible light.

My improved ink comprises a resinous material speclfically insoluble in dry cleaning solvents, but soft and liquid when subjected to the action of steam; an acid salt of a colorless, fluorescent, basic compound, both of which are carried in a suitable liquid vehicle. The color- Water milliliters Glycerine do lsopmpyl alr-n'hnl do 30 An acid salt grams 4 A suitable resinous material do 1 the last two dissolved in the mixture of the first three.

For the rersinous material to enhance the fluorescence I have successfully used a polyvinyl alcohol resin. For the acid salt of the colorless fluorescent, basic compound I have successfully used any one of the following compounds:

(1) Hydrochloride salt of alpha phenyl meta amino benzimidazole (2) Hydrochloride salt of alpha phenyl meta amino benzoxazole (3) Hydrochloride salt of alpha phenyl meta amino benzthiazole (4) Hydrochloride salt of meta amino beta methyl coumarine For the liquid vehicle I have successfully used a mixture of approximately three parts by volume of water, four parts by volume of glycerine and three parts by volume of isopropyl alcohol.

I do not desire to be understood as limiting my invention to the specific compounds mentioned heretofore, as I know that other similar classes of compounds will react and function in a similar manner to produce similar results. The ones mentioned are simply illustrative.

I have demonstrated that the component called acid salt of a colorless, fluorescent, basic compound has the following characteristics:

1. It is well known by skilled dye chemists that acid salts of basic dyestuffs are good Wool dyestuil's, and my acid salts of colorless, fluorescent. basic compounds act in a similar manner;

2. They are insoluble in organic solvents, such as are commonly used in dry cleaning operations;

3. They are only weakly fluorescent when sub jected to the action of ultraviolet rays; and

4. They are easily convertible by the application of steam back to the parent compound or free base.

From the foregoing it is seen that identification markings made upon fabrics with the ink are, without further processing, entirely unsatisfactory for purposes of invisible fluorescent identification. It does, however, have that important characteristic of being fast to the fibers of the fabric and capable of withstanding the action of the solvents used in dry cleaning.

When, however, the acid salts have hydrolized to the parent compounds during the pressing operation of dry cleaning, the parent compounds comprising the marks will have the following characteristics:

1. They will be colorless and invisible under ordinary light but brilliantly fluorescent and readily legible under ultraviolet rays;

2. They will be soluble under the application of ordinary dry cleaning solvents and thereby removable in subsequent dry cleaning operations; and

3. They will be basic. The chemical reaction of hydrolysis" may be shown as follows:

parent compound or free base The hydrochloride salt of alpha phenyl meta amino benzimidazole, upon reaction with a molecule of water in the form of steam, will produce the free base alpha phenyl meta amino bcnzimidazole, free hydrochloric acid, and regenerate the water molecule. The steam, or rather the water molecule, does not enter into the reaction. The acid liberated in the fibers is very minute in amount and is rapidly diluted and swept away by the excess steam.

I have demonstrated that a similar reaction would take place under the influence of dry heat alone, but much higher temperatures are then necessary.

In the accompanying claims where reference is made to the application of heat in the pressing operation, I intend to include the usual steam heat of a pressing operation and also a higher degree of dry heat.

The dry cleaning solvents now in general use for dry cleaning operations are Stoddard solvent, carbon tetrachloride, trichlor-ethylene, Sanitone, etc., and I have demonstrated that when these or similar solvents are used, the said acid salt component of the ink applied to th fabric will not be appreciably affected. I have also demonstrated that after the acid salt has been chemically reacted by heat and steam as set Steam mil - forth, the resulting basic compound, for example the alpha phenyl meta amino benzimidazole, is soluble in such solvents and will be removed from the fabric by subsequent dry cleaning operations.

I have had satisfactory results with an ink' composed of four grams of the hydrochloride salt of alpha phenyl meta amino benzimidazole and one gram of a polyvinyl alcohol resin dissolved in a mixture of thirty milliliters of water, forty milliliters of glycerine and thirty milliliters of isopropyl alcohol.

In practice, I preferably apply the ink to a laundry marking machine and from it impress the marking upon the fabric. Then the fabric is dry cleaned by applying the usual solvents, in which step the markings are not removed or changed. Then, when the fabric is pressed, the acid salt component is hydrolized and it, together with the resinous material, is dispersed into and around the fibers or the fabric and forms a substantiallly colorless, translucent, highly fluorescent coating arranged in the pattern of the applied marking; Under normal light the markings are substantially invisible and, hence, not objectionable in ordinary use of the fabric.

When, however, under conditions of darkness or dim light, rays from an ultraviolet lamp, from which the visible light is screened out by suitable filters, are applied to the fabrics, the markings lappear to be highly fluorescent and clearly legi- As to the source of the ultraviolet rays for producing the fluorescence in the marks, I have successfully employed the 22" and 50" General Electric NiCo tube, the General Electric 1-1-4 #T-lfi black bulb, and the General Electric 25! watt Wonder bulb, all of which lamps are equipped with Corning ultraviolet filters as an integral part of the lamp. I have also used the General Electric H- #T-l2 100 watt and the H-5 #T-lZ 250 watt bulbs together with 2. Corning Nos. 584, 585, 586, 587 or 597 ultraviolet filters. The above mentioned filters eliminate most of the rays other than those of the usual ultraviolet range (3000 to 4000 Angstrom units).

An operator soon learns by experiment just how dim the light should be in order to produce the maximum visible fluorescence in the marks, and the lighting of the operating room is there-= after regulated accordingly. My use of the term under ultraviolet rays is intended to include the substantial exclusion of visible light.

I claim as my invention:

1. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent, and a hydrochloride salt of alpha phenyl meta amino benzimidazole.

2. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent, and a hydrochloride salt of alpha phenyl meta amino benzthiazole.

3. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent, and a hydrochloride salt of meta amino beta methyl coumarine.

4. The method of invisible identification marking of fabrics to be subjected to a dry cleaning operation, which consists in applying a mark to the fabric with an ink comprising a viscous liquid vehicle, an acid salt of a substantially colorless, basic, fluorescent compound and a resinous material substantially insoluble in commercial dry cleaning solvents, then subjecting the fabric to a dry cleaning operation to substantially remove the liquid vehicle, then applying steam to the fabric and thereby causing the acid salt to revert to its parent compound and to thereby become brilliantly fluorescent under ultraviolet rays, and also to become soluble under the application of ordinary dry cleaning solvents, said application of steam also causing the resinous material to disperse throughout the marked area of the fabric and, together with the parent compound of the acid salt, form on the fibers of the fabric a sub stantially colorless, translucent coating to thereb increase the fluorescence of the said parent compound, and to thereby form an identification mark substantially invisible in normal light but fluorescent and clearly visible upon the application of ultraviolet rays in dim visible light.

5. The method of invisible identification marking of fabrics to be subjected to a dry cleaning operation, which consists in applying a mark to the fabric with an ink comprising a viscous liquid vehicle, an acid salt of a substantially colorless, basic, fluorescent compound and a resinous material substantially insoluble in commercial dry cleaning solvents, then applying steam to the fabric and thereby causing the acid salt to revert to its parent compound and to thereby become brilliantly fluorescent under ultraviolet rays, and also to become soluble under the application of ordinary dry cleaning solvents, said application of steam also causing the resinous material to disperse throughout the marked area of the fabric and, together with the parent compound of the acid salt, form on the fibers of the fabric a substantially colorless, translucent coating to thereby increase the fluorescence of the said parent compound, and to thereby form an identification mark substantially invisible in normal light but fluorescent and clearly visible upon the application of ultraviolet rays in dim visible light.

6. The method of invisible identification marking of fabrics to be subjected to a dry cleaning operation, which consists in applying a mark to the fabric with an ink comprising a viscous liquid vehicle, an acid salt of a substantially colorless, basic, fluorescent compound and a resinous material substantially insoluble in commercial dry cleaning solvents, then applying steam to the fabric and thereby causing the acid salt to revert to its parent compound and to thereby become brilliantly fluorescent under ultraviolet rays, said application of steam also causing the resinous material to disperse throughout the marked area of the fabric and, together with the parent compound of the acid salt, form on the fibers of the fabric a substantially colorless, translucent coating to thereby increase the fluorescence of the said parent compound, and to thereby form an identification mark substantially invisible in normal light but fluorescent and clearly visible upon tapplication of ultraviolet rays in dim visible 1g 7. The method of invisible identification marking of fabrics to be subjected to a dry cleaning operation, which consists in applying a mark to the fabric with an ink comprising a viscous liquid vehicle, an acid salt of a substantially colorless, basic, fluorescent compound and a resinous material substantially insoluble in commercial dry cleaning solvents, then applying heat to the'fabric in an amount sufficient to cause the acid salt to revert to its parent compound and to thereby become brilliantly fluorescent under ultraviolet rays, said application of heat also causing the resinous material to disperse throughout the marked area of the fabric and, together with the parent compound of the acid salt, form on the fibers of the fabric a substantially colorless, translucent coating to thereby increase the fluorescence of the said parent compound, and to thereby form an identification mark substantially invisible in normal light but fluorescent and clearly visible upon the application of ultraviolet rays in dim visible light.

8. An ink for marking fabrics which are to be subjected to a dry cleaning operation, the marks being substantially invisible and capable of becoming brilliantly fluorescent and readily visible upon the application of ultraviolet rays or the like, comprising a viscous liquid vehicle, and acid salt of a colorless, fluorescent basic compound having the characteristic that when subjected to the action of steam it will hydrolize to its parent compound, and thereby become brilliantly fluorescent under ultraviolet rays and also become soluble in dry cleaning solvents and a resinous material characterized by becoming softened and dispersed, with the said parent compound, in and around the fibres of a fabric and to form a translucent coating for the fibres for increasing the fluorescence of the mark under ultraviolet rays.

9. An ink for marking fabrics which are to be subjected to a dry cleaning operation, the marks being substantially invisible and capable of becoming brilliantly fluorescent and readily visible upon the application of ultraviolet rays or thelike, comprising a viscous liquid vehicle, an acid salt of a colorless, fluorescent basic compound having the characteristic that when subjected to the action of steam it will hydrolize to its parent compound, and become brilliantly fluorescent under ultraviolet rays, and a resinous material substantially insoluble in dry cleaning solvents and characterized by becoming softened and dispersed, with the said parent compound, in and around the fibres of a fabric and to form a translucent coating for the fibres for increasing the fluorescence of the mark under ultraviolet rays.

10. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterizedby being substantially colorless and translucent and in soluble in commercial dry cleaning solvents, and an acid salt of a colorless, fluorescent basic compound, selected from a group consisting of hydrochloride salt of alpha phenyl meta amino benzimidazole, hydrochloride salt of alpha phenyl meta amino benzoxazole, hydrochloride salt of alpha phenyl meta amino benzthiazole, and the hydrochloride salt of meta amino beta methyl coumarine.

11. An in]: for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent and insoluble in commercial dry cleaning solvents, and an acid salt of the colorless, fluorescent basic compound, meta amino beta methyl coumarine.

12. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent and insoluble in commercial dry cleaning solvents, and an acid salt of the colorless, fluorescent basic compound, alpha phenyl meta amino benzimidamole.

13. An ink for the identification marking of fabrics, comprising a liquid vehicle in which is carried a resinous material characterized by being substantially colorless and translucent and insoluble in commercial dry cleaning solvents, and an acid salt of the colorless, fluorescent basic compound, alpha phenyl meta amino benzthiasole.

14. An ink for marking fabrics to be subjected to dry cleaning and capable of making marks on the fabrics which are substantially invisible and insoluble in dry cleaning solvents and, upon application of heat or steam, remain invisible under ordinary light but become brilliantly fluorescent under ultraviolet rays or the like and soluble in dry cleaning solvents, comprising a liquid carrier having disolved therein an acid salt of a colorless, fluorescent basic compound hydrolizable under heat or steam to the said colorless, fluorescent basic compound.

15. An ink for marking fabrics to be subjected to dry cleaning and capable of making marks on the fabrics which are substantially invisible and insoluble in dry cleaning solvents and, upon application of heat or steam, remain invisible under ordinary light but become brilliantly fluorescent under ultraviolet rays or the like and soluble in dry cleaning solvents, comprising a liquid carrier having dissolved therein an acid salt of a colorless, fluorescent basic compound, hydrolyzable under heat or steam to the said colorless, fluorescent basic compound, and a resinous material.

16. An ink for marking fabrics to be subjected to dry cleaning and capable of making marks on the fabrics which are substantially invisible and insoluble in dry cleaning solvents and, upon application of heat or steam, remain invisible under ordinary light but becom brilliantly fluorescent under ultraviolet rays or the like and soluble in dry cleaning solvents, comprising a liquid carrier having dissolved therein an acid salt of a colorless, fluorescent basic compound, hydrolyzeble under heat or steam'to the basic compound and a polyvinyl alcohol resin.

17. An ink for the identification marking of fabrics comprising a liquid vehicle carrying an acid salt of a colorless, fluorescent compound selected from the group consisting of alpha phenyl meta amino benzimidazole, alpha phenyl meta amino benzoxazole, alpha phenyl meta amino benzthiazole and meta amino beta methyl coumarine.

18. An ink for the identification marking of fabrics comprising a liquid vehicle carrying an acid salt of meta amino beta methyl coumarine.

19. An ink for the identification marking of fabrics comprising a liquid vehicle carrying an acid salt of alpha phenyl meta amino benzimidazole.

20. An ink for the identification marking of fabrics comprising a liquid vehicle carrying an acid salt of alpha phenyl meta amino benzthiazo e.

JOHN MIGLARESE. 

